Auto-stick shift issue

[pfive]

I love my semi auto tranny, but for the past few weeks it would at time shift me from 4th to 3rd w/o warning. my engine light comes on for a second them the tranny works as it should. I've brought it in but since there is no code, they cant do anything for it.

has anyone else had this issue.

my ride is an 02.5 Pfive.

 

[wmbeaver]

mine will shift down automatically when i start slowing down, but i havent seen an engine light yet

 

[pfive]

the tranny will jolt me into 3rd at 60 mph...the second time, it just put it into auto w/o notice...its odd. i think its electrical, but nontheless, i am pretty pissed about it

 

[wmbeaver]

the tranny will jolt me into 3rd at 60 mph...the second time, it just put it into auto w/o notice...its odd. i think its electrical, but nontheless, i am pretty pissed about it

yea, cant say ive had that happen, but mine is an o3

 

[evilmonkeyMSP]

mine is an 02.5 w/ the manumatic...I cant say that this has ever happened to me tho...mine shifts effortlessly & i havent experienced and ackward down shifts...sorry

 

[pfive]

it's so uncommon that i cant pinpoint it. i cant bring it to the shop becuase there is no light. they will just say "well, there was no code", so i either have to wait for it to happen again and the light to stay on or troubleshoot. it's also been butt cold up here... my pfive does not like to be cold.

 

[pasadena_commut]

the tranny will jolt me into 3rd at 60 mph...the second time, it just put it into auto w/o notice...its odd. i think its electrical, but nontheless, i am pretty pissed about it

At the time were you climbing a hill, or did you step on the gas? That can cause an abrupt downshift from 4th to 3rd when the transmission is in the fully automatic mode. However it doesn't usually shift immediately back to the higher gear, it usually stays in the lower gear until the conditions change again (less steep, less gas, whatever). I don't know if it will do that in the semi-automatic mode under the same conditions or not, but guess that it might, as in the semi-automatic mode it only allows so much leeway before it shifts for you.

However I've never seen a CEL accompany a downshift.

You may be right that it is an electrical problem, but sadly those can be really hard to nail down - there are so, so many electrical connectors. At the very least check that both battery cables are on really well, that the primary ground is good, and that none of the fuses is loose. You might also want to try wiring an old fashioned voltmeter onto the 12V power, perhaps at the cigarette lighter. Then if you look at the meter fast enough you can see if the main power did something odd, since the needle will still be swinging. Or put an led test lamp in there and see if it flickers. Not an incandescent test lamp, if the voltage glitch is really short the filament may not cool enough in that time for you to see it.

 

[pfive]

i rarely drive the car in full auto. its always in manual mode and its very responsive. it would knock me out of 4th out of nowhere w/o warning, up a hill or flat. the manual mode is indeed electronic and hard to nail down. i had a camshaft sensor replaced a few weeks ago which threw on the engine light..and the car did the same thing that the sensor went. who knows. it's under warranty, so it wont cost me much to have looked at if i need to.

 

[Crazee D]

Never happened to me either....yet.
Maybe time for a flush?

 

[pfive]

Never happened to me either....yet.
Maybe time for a flush?

fluid was just changed.... i notice now there is a hissing/whining coming from the radio, and when that happens, the headlights rim dim when i apply the brakes, signals, etc. there is also a clicking coming from the center colsole when i apply the brake in park. i am thinking it's electrical.

 

[killer B]

haven't had that happen to me, however sometimes the shfter gets stuck in park. and sometimes in sticks coming from drive to park......you just have to try a few times then it's all good. but this happens few and far between. anybody else have this happen?

 

[evilmonkeyMSP]

sounds like the transmission lock relay is going on yours...it went on mine...

haven't had that happen to me, however sometimes the shfter gets stuck in park. and sometimes in sticks coming from drive to park......you just have to try a few times then it's all good. but this happens few and far between. anybody else have this happen?

 

[wmbeaver]

fluid was just changed.... i notice now there is a hissing/whining coming from the radio, and when that happens, the headlights rim dim when i apply the brakes, signals, etc. there is also a clicking coming from the center colsole when i apply the brake in park. i am thinking it's electrical.

i get a clicking noise when i do brakes in park, but nothing really noticable

i have no clue about the other stuff, btu i would guess something with the alternator

 

[pfive]

i get a clicking noise when i do brakes in park, but nothing really noticable

i have no clue about the other stuff, btu i would guess something with the alternator

im going to get my belts replaced (they are starting to squeek) and ill see where it goes from there...

 

[evilmonkeyMSP]

if its a click that comes from the shifter area when you press the brakes while in park, that is the locking mechanism in the shifter "unlocking" so you can take it out of park

i get a clicking noise when i do brakes in park, but nothing really noticable

i have no clue about the other stuff, btu i would guess something with the alternator

 

[i12drivemyMP5]

My first guess would be the unit on the front of the tranny where the shift cable attaches. Isn't that some electrical relay thing that tells the tranny what to do when the cable moves to different positions?

 

[pfive]

My first guess would be the unit on the front of the tranny where the shift cable attaches. Isn't that some electrical relay thing that tells the tranny what to do when the cable moves to different positions?

i think so...this morning there was rattling going on in there...but i have not had a shifting problem since my first port. i got used to keeping my hand on the shifter and i think that it would move a bit possible confusing sensors, so now i dont keep my hand on it when in 4th and it hasnt happened. i did drop a combo into the console where the brake is, but i dont think that would cause a bad shift. im going to have it checked out anyways...